1. The Field of the Invention
The present invention relates to an electrode connector. More particularly, this invention relates to an electrode connector that securely engages a flexible electrode without permanently deforming the flexible electrode.
2. The Relevant Technology
Electrodes and electrode connectors are commonly used in the medical industry to monitor the physiological functioning of the human body that results in certain electrical phenomenons. The electric signals are typically monitored, for example, by electrocardiographic instrumentation. In most cases, the electrocardiographic instrumentation includes a lead cable, an electrode connector, and an electrode. The lead cable is connected to the instruments, and the electrode is attached to the skin of the patient. Connectors are used to connect the lead cable and the electrode. The electrode is often attached to the skin of the patient by various methods including tape or a suction cup used in combination with an electrically conductive gel or cream when it is attached to the electrode connector.
There are many different designs of electrode connectors that are currently available. The electrode connector must be able to securely fasten the electrode connector to an electrode. One reason it is important that the connector be securely attached to the electrode is to avoid shocking the patient or separating from the electrode when the patient moves. Any movement by the patient causes dislocating forces between the electrode connector and the contact portion of the flexible electrode. The electrode connector also needs to be durable so that it can be repeatedly used. It is important that the electrode connector have a relatively long life. Further, a good connection must be maintained so that the instruments can accurately read and interpret the electric signals.
There has been a recent movement in the medical field to utilize electrodes that are somewhat flexible. In fact, in some cases a portion of the flexible electrode actually acts as the contact area of the electrode. The flexible electrode is usually directly attached to the skin of the patient which in some cases may be for an extended period of time.
One type of electrode connector that is commonly used in the medical field is a variation of what is known as an electrical alligator clip. Typically, the electrical alligator clip is an industrial alligator clip with a plastic sheath that has been heat shrunk thereover to extend over the majority of the portion of the clip body. The open-jaw portion of the alligator clip closes on the contact portion of the electrode to securely hold the electrode therebetween. One variation on this type of design is that the alligator clip has a combination of side serrated teeth and opposed rows of parallel teeth for grasping the electrode. This design allows the electrode connector to grasp an exposed contact edge of the flexible electrode.
Other types of electrode connectors that are available include an electrode connector that is basically an alligator clip but holds the flexible electrode using a prong which actually stretches and deforms the contact area of the flexible electrode as the alligator clip closes. The contact of the flexible electrode is pinched between the prong and the opening in the jaw of the alligator clip itself. As the jaws of the alligator clip close, the prong actually stretches and permanently deforms the flexible electrode until the contact or flexible electrode is positioned in the recess or opening that receives the prong. One problem associated with a connector that permanently deforms the electrode in order to establish a strong electrical contact is that if the electrode does not consist of a material which can be stretched and/or deformed by the prong of the alligator clip, it cannot be used with this alligator clip or will not form a strong electrical contact. Further, as there is the possibility that the materials will not form a good contact with the jaws of the alligator clip itself, the connector is less effective in making a secure contact with the electrode.
In those cases that the electrode connector becomes separated from the electrode, perhaps because of movement by the patient, an electrode with a contact area that has been deformed by the prong of the electrode connector may not be able to form a good connection upon being reattached to the connector. In this case, the electrode must be removed and a new, nondeformed electrode be reattached to the patient. This is time consuming and wasteful. Further, frequent replacement of the electrode can result in irritation and even damage of the skin of the patient, particularly on those patients such as an elderly patient who may have fragile skin.
Other types of electrode connectors that are available have the drawback that it is not possible for the user of the electrode connector to know for sure that when the jaws of the connector close, the positioning of the contact area is aligned with the correct spot on the connector. An additional drawback to available electrode connectors is that there are times that because of a patient moving or for some reason such as the wires attached to the electrode connector becoming tangled with another medical instrument that the electrode connector may be accidentally disconnected from the flexible electrode.
What is needed is an electrode connector which provides a visual indication that the flexible electrode is correctly positioned relative to the electrode connector so that a good electrical connection can be formed. Further, an electrode connector is needed that cannot be accidentally disconnected from the flexible electrode. Finally, there is a need for an electrode connector which forms a good electrical connection without permanently deforming the flexible electrode.